right ventricular hemodynamic alteration after pulmonary valve replacement in children with congenital heart disease

introduction:  in patients who underwent surgery to repair tetralogy of fallot, right ventricular dilation from pulmonary regurgitation may be result in right ventricular failure, arrhythmias and cardiac arrest. hence, pulmonary valve replacement may be necessary to reduce right ventricular volume overload. the aim of present study was to assess the effects of pulmonary valve replacement on right ventricular function after repair of tetralogy of fallot.   materials and  method:  this retrospective study was carried out between july 2011 and october 2013 on 21 consecutive patients in chamran heart center (esfahan). the study included 13 male (61.9%) and 8 female (38.1%). cardiac magnetic resonance was performed before, 6 and 12 months after pulmonary valve replacement in all patients (babak imaging center, tehran) with the 1.5 tesla system. the main reason for surgery at tetralogy of fallot repaired time was tetralogy of fallot + pulmonary insufficiency (17 cases) and tetralogy of fallot + pulmonary atresia (4 cases). right ventricular function was assessed before and after pulmonary valve replacement with two-dimensional echocardiography and ttest was used to evaluate follow-up data.   results:  right ventricular end-diastolic volume, right ventricular end- systolic volume significantly decreased (p value ˂ 0.05).right ventricular ejection fraction had a significant increase (p value ˂ 0.05). right ventricular mass substantially shrank after pulmonary valve replacement. moreover, pulmonary regurgitation noticeably decreased in patients. the other hemodynamic parameter such as left ventricular ejection fraction improved but was not significant (p value= 0.79). conclusion:  pulmonary valve replacement can successfully restores the impaired hemodynamic function of right ventricle which is caused by direct consequence of volume unloading in patient. pulmonary valve surgery in children with tetralogy of fallot who have moderate to severe pulmonary regurgitation leads to an improvement of right ventricular function.